Vein harvesting system including dilator shaft and removable retractor housing

ABSTRACT

The invention provides a system and method for harvesting a vessel section. The system includes an endoscope, at least one harvesting tool, and an elongated instrument including a shaft and a housing. The shaft includes a viewable region along a length of the shaft and a lumen to slidably receive the endoscope. The housing is releasably engaged with the shaft and includes an elongated opening to provide a working area adjacent to a vessel for the harvesting tool. The method includes making an incision at a point corresponding to the proximal end of the vessel section to be harvested. A shaft is inserted through the incision and adjacent to the vessel section. A housing is slidably engaged with the inserted shaft. Harvesting operations are performed in a working area defined by sidewalls of the housing. The harvesting operations are visually monitored through the shaft.

This application claims the benefit of U.S. Provisional Application No.60/583,004, filed Jun. 25, 2004 (the entire contents of which areincorporated by reference).

TECHNICAL FIELD

This invention relates generally to biomedical systems and methods. Morespecifically, the invention relates to systems and methods forharvesting a vessel section.

BACKGROUND OF THE INVENTION

Heart disease, specifically coronary artery disease, is a major cause ofdeath, disability, and healthcare expense in the United States and otherindustrialized countries. A common form of heart disease isatherosclerosis, in which the vessels leading to the heart are damagedor obstructed by plaques containing cholesterol, lipoid material,lipophages, and other materials. When severely damaged or obstructed,one or more of the vessels can be replaced during a coronary arterybypass graft (CABG) procedure. CABG surgery is performed about 350,000times annually in the United States, making it one of the most commonlyperformed major operations.

To prevent rejection, the graft material is preferably a blood vesselharvested from elsewhere within a patient's body. The most commonly usedbypass vessel is the saphenous vein from the leg. Because the venoussystem of the leg is redundant, other veins that remain within thepatient's leg are adequate to provide return blood flow followingremoval of the saphenous vein.

Various methods have been used to harvest the saphenous vein. Untilrecently, the typical procedure involved making a single long incision,extending from a patient's groin to at least the knee and often to theankle. This method results in substantial postoperative pain, withpatients frequently complaining more about discomfort from the site ofleg vein harvesting than about their CABG surgery wound. In addition,the extensive incision site is subject to infection and delayed healing,especially in patients with poor circulation, which not infrequentlyaccompanies coronary artery disease. The disfiguring scar from such alarge incision is also of concern to some patients.

Less invasive procedures are preferred, and surgical devices andtechniques now exist that allow the saphenous vein to be harvestedthrough one or more small, transverse incisions, generally using anendoscope. Endoscopic procedures yield reduced wound complications,reduced discomfort, and superior cosmetic results compared withtraditional methods of vein harvesting. Equipment for endoscopic veinharvesting is frequently complex, having multiple parts that aredifficult, if not impossible, for one person to manipulate withoutassistance.

Therefore, it would be desirable to have a system and a method forharvesting a vessel section that overcome the aforementioned and otherdisadvantages.

SUMMARY OF THE INVENTION

One aspect of the present invention is a device for harvesting a vesselsection, e.g., a saphenous vein section. The device comprises a shaftand a housing. The shaft includes a lumen extending from a proximal endof the shaft into a nose portion of the shaft. The shaft furtherincludes a viewable region along a length of the shaft. The housing isreleasably engaged with the shaft and includes an elongated opening toprovide a working area adjacent to a vessel.

Another aspect of the present invention is a system for harvesting avessel section, e.g., a saphenous vein section. The system comprises anendoscope, at least one harvesting tool, and an elongated instrumentcomprising a shaft and a housing. The shaft includes a viewable regionalong a length of the shaft and a lumen to slidably receive theendoscope. The housing is releasably engaged with the shaft and includesan elongated opening to provide a working area adjacent to a vessel forthe harvesting tool.

Yet another aspect of the present invention is a method for harvesting avessel section, a saphenous vein section. An incision is made in a bodyat a point corresponding to a proximal end of the vessel section to beharvested. A shaft is inserted through the incision and adjacent to thevessel section. A housing is slidably engaged with the inserted shaft.Harvesting operations are performed in a working area defined bysidewalls of the housing. The harvesting operations are visuallymonitored through the shaft.

The aforementioned and other features and advantages of the inventionwill become further apparent from the following detailed description ofthe presently preferred embodiments, read in conjunction with theaccompanying drawings. The detailed description and drawings are merelyillustrative of the invention rather than limiting, the scope of theinvention being defined by the appended claims and equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the shaft of one embodiment of a device forharvesting a vessel section, in accordance with the present invention;

FIG. 2 is an enlarged cross-sectional view of the shaft of FIG. 1;

FIG. 3 is an illustration of the housing of one embodiment of a devicefor harvesting a vessel section, in accordance with the presentinvention;

FIG. 4 is an enlarged cross-sectional view of the housing of FIG. 3;

FIG. 5 is an illustration of the shaft of FIG. 1 and the housing of FIG.3 engaged to form one embodiment of a device for harvesting a vesselsection, in accordance with the present invention;

FIG. 6 is an enlarged cross-sectional view of the device of FIG. 5;

FIG. 7 is a view of the handle section of FIG. 4 seen from its proximalend;

FIG. 8 is an illustration of one embodiment of a system for harvesting avessel section, in accordance with the present invention; and

FIG. 9 is a flow diagram of one embodiment of a method for harvesting avessel section in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention is a device for harvesting a vesselsection, e.g., a saphenous vein section. One embodiment of the device,in accordance with the present invention, is illustrated in FIGS. 1-6,in which like elements share like numbers. The figures are not to scale.The device comprises a shaft 110, a housing 120, and a handle 130.Housing 120 removably engages with shaft 110.

Shaft 110 is illustrated in FIG. 1, with an enlarged cross-section shownin FIG. 2. Shaft 110 includes a distal nose portion 112 that is used tobluntly dissect tissue away from a vessel being harvested, therebydilating an area adjacent to the vessel section. As used in thisspecification, the terms “distal” and “proximal” are with reference tothe operator when the device is in use. Nose portion 112 is shown inFIG. 1 to be roughly cone shaped with a spherical tip, however the noseportion 112 may assume alternative shapes that are also acceptable forblunt dissection.

Shaft 110 is made of one or more appropriate biocompatible materials,including, but not limited to, a polymer and/or a metal. For example,shaft 110 may comprise stainless steel. Preferably, at least a portionof shaft 110 comprises a transparent material. In the presentembodiment, both nose portion 112 and a bottom portion 114 of shaft 110are transparent, thus ensuring that regions adjacent to the nose portionand along the length of the shaft are viewable using an instrument suchas an endoscope. As illustrated in FIGS. 1 and 2, nose portion 112,bottom portion 114, and body portion 116 are formed individually andassembled to form shaft 110. However, in another embodiment, shaft 110may be formed as a single, unitary structure, with the entire structurecomprising, for example, a transparent material.

Transparent bottom portion 114 is substantially planar and forms aportion of the wall of a lumen 118, as seen in FIG. 2, that extends froma proximal end of shaft 110 into nose portion 112. The shape of lumen118 may be varied to best accommodate an endoscope. The shape of bottomportion 114 is intended to maximize the optical properties of theportion and may be varied for optimum viewing through the portion.

Housing 120, illustrated in FIG. 3 and in enlarged cross-section in FIG.4, comprises one or more appropriate biocompatible materials such as apolymer and/or metal. Housing 120 includes an elongated opening toprovide a working area 122 adjacent to a vessel (not shown). Thus,housing 120 acts as a retractor. In the present embodiment, working area122 extends along the entire length of housing 120 and is defined by thewalls of housing 120. As shown in FIG. 4, the walls of housing 120 arecurved. In another embodiment, the walls may be straight; however,curved walls can provide a smoother surface for introducing the housinginto a body and positioning the housing adjacent to a vessel.

Housing 120 may be connected to a light source (not shown) and transmitlight from the light source into the working area. This may beaccomplished by, for example, forming housing 120 from a transparentacrylic, including optical fibers within the housing, or lining thehousing with an optical lighting film to form a light pipe.

Housing 120 includes an elongated slot 124 that allows housing 120 to beengaged with shaft 110. Slot 124 opens into working area 122. Thus, whenhousing 120 is engaged with shaft 110, as seen in FIG. 5 and in enlargedcross-section in FIG. 6, an endoscope positioned within shaft lumen 118can view through the bottom portion 114 of shaft 110 and into workingarea 122. One or more tabs (not shown) may span slot 124 to providegreater rigidity and structural integrity of housing 120, resulting inslot 124 having more than one opening into working area 122.

The described design allows housing 120 to be engaged with shaft 110,with a portion of shaft 110 received within slot 124 as shown in FIGS. 5and 6. Housing 120 slides onto shaft 110 at a proximal end of the shaftand is advanced over the shaft toward nose portion 112 until both arepositioned as shown in FIG. 5. It will be apparent to one skilled in theart that various other designs for a shaft and housing would permit thehousing to be releasably engaged with the shaft. For example, the shaftmight include side extensions that are received within grooves in thehousing, much like a tongue and groove assembly. In another example, thehousing might include individual tabs to engage the shaft.

In the present embodiment, handle 130 is divided into two sections, withhandle section 132 (seen in FIGS. 1 and 7) attached to a proximalportion of shaft 110, and handle section 134 (seen in FIGS. 2 and 7)attached to a proximal portion of housing 120. Handle section 134includes a cavity 133, shown in phantom in FIG. 3, within which aportion of handle section 132 is received as seen in FIG. 5. This designprovides a handle that is narrower than the combined widths of the twohandle sections when the shaft and housing are engaged and offers theconvenience of having a handle on each of shaft 110 and housing 120 whenthe two elements are separate. In another embodiment, a single handle,for example a removable handle, may be attached to either the shaft orthe housing.

The device includes passageways for an endoscope to be received withinlumen 118 and at least one tool to be received within working area 122.The endoscope passageway opens into lumen 118 at the proximal end ofshaft 110, while the tool passageway opens into working area 122 at theproximal end of housing 120. Where any portion of the handle wouldotherwise block these openings, the handle includes endoscope and toolpassageways. For example, in the present embodiment, the lower portionof handle section 134 forms a proximal end of housing 120, therebyblocking the opening at the proximal end of housing 120 into workingarea 122. In addition, the upper portion of handle section 134 isproximal to and, therefore, blocks the opening into lumen 118 when shaft110 and housing 120 are engaged. To provide openings into lumen 118 andworking area 122, handle section 134 includes an endoscope passageway136 and two tool passageways 138, as can be seen in FIG. 7, which showshandle section 134 viewed from its proximal end. Endoscope passageway136 provides communication with lumen 118, while tool passageways 138open into working area 122 to allow harvesting tools access to the area.

Another aspect of the present invention is a system for harvesting avessel section, e.g., a saphenous vein section. One embodiment of thesystem, in accordance with the present invention, is illustrated in FIG.8. The system comprises an elongated instrument 805, an endoscope 815,and at least one harvesting tool 825.

Elongated instrument 805 is a device such as has been described indetail above and illustrated in FIGS. 1-7. Elongated instrument 805comprises a shaft 810, a housing 820, and a handle 830. Shaft 810 isused to dilate an area adjacent to the vessel section being harvested bybluntly dissecting tissue away from the vessel while visually monitoringthe process using endoscope 815. Housing 820 provides a working areaadjacent to the vessel for the harvesting tool(s) 825. Thus, housing 820acts as a tissue retractor.

Shaft 810 is made of one or more appropriate biocompatible materials,such as a polymer or a metal, e.g., a stainless steel. Preferably, atleast a portion of shaft 810 comprises a transparent material. In thepresent embodiment, both a distal nose portion 812 and a bottom portion814 of shaft 810 are transparent to ensure that regions adjacent to thenose portion and along the length of the shaft are viewable usingendoscope 815.

Transparent bottom portion 814 is substantially planar and forms aportion of the wall of a lumen (e.g., as seen in FIG. 2 at 118) thatextends from a proximal end of shaft 810 into nose portion 812. Thelumen is sized to allow endoscope 815 to slide within the lumen forviewing along the length of the shaft through bottom portion 814.Endoscope 815 is, preferably, a four- or five-millimeter (4- or 5-mm),thirty-degree (30°) endoscope; however, other endoscopes may be used inthe present invention. The shape of bottom portion 814 is intended tomaximize the optical properties of the portion and may be varied inanother embodiment.

Housing 820 has an elongated opening that provides a working area 822for harvesting tool(s) 825 adjacent to the vessel to be harvested. Thus,housing 820 acts as a retractor. Housing 820 may be connected to a lightsource (not shown) and transmit light from the light source into theworking area. This may be accomplished by, for example, forming housing820 from a transparent acrylic, including optical fibers within thehousing, or lining the housing with an optical lighting film to form alight pipe.

In the present embodiment, housing 820 includes a slot 824 that allowshousing 820 to be engaged with shaft 810, with a portion of shaft 810received within slot 824. Slot 824 opens into working area 822. Thus,when housing 820 is engaged with shaft 810, an endoscope positionedwithin shaft lumen 816 can view through bottom portion 814 of shaft 810and into working area 822. One or more narrow structures (not shown) mayspan slot 824 to provide greater rigidity and structural integrity ofhousing 820.

The described design allows housing 820 to slide onto shaft 810 at aproximal end of the shaft and be advanced over the shaft toward distalnose portion 812. FIG. 8 shows housing 820 partially engaged with shaft810, with housing 820 capable of sliding further along shaft 810 untilthe end of the housing is aligned with the end of the shaft as seen inFIG. 6. It will be apparent to one skilled in the art that various otherdesigns for a shaft and housing would permit the housing to bereleasably engaged with the shaft, including a tongue and groove designor tabs extending from the housing to engage the shaft.

Handle 830 is divided into two sections, with handle section 832attached to a proximal portion of shaft 810, and handle section 834attached to a proximal portion of housing 820. Handle section 834includes a cavity 833 within which a portion of handle section 832 isreceived when shaft 810 and housing 820 are fully engaged. This designprovides a handle that is narrower than the combined widths of the twohandle sections when the shaft and housing are engaged and offers theconvenience of having a handle on each of shaft 810 and housing 820 whenthe two elements are separate. In another embodiment, a single handle,for example a removable handle, may be attached to either the shaft orthe housing.

Elongated instrument 805 includes passageways to allow endoscope 815 tobe received within lumen 818 and at least one harvesting tool 825 to bereceived within working area 822. The endoscope passageway may be simplyan opening through the proximal end of shaft 810 into the shaft lumen,while the tool passageway may be an opening into working area 822 at theproximal end of housing 820. Where any portion of handle 830 wouldotherwise block such openings, as is the case in the present embodiment,the handle includes endoscope and tool passageways such as those seen inFIG. 7 at 136 and 138, respectively. As described above, when shaft 810and housing 820 are engaged, the endoscope passageway is incommunication with the shaft lumen, and the tool passageways open intothe working area to allow harvesting tools access to the area. A cuttingtool 825 is shown in FIG. 8. Other harvesting tools, for example toolsto lift or move the vessel being harvested, may be included in thesystem.

Yet another aspect of the present invention is a method for harvesting avessel section. FIG. 9 shows a flow diagram of one embodiment of themethod in accordance with the present invention.

An incision is made in a body at a point corresponding to a proximal endof the vessel section to be harvested (Block 905). An endoscope isinserted into the lumen of a shaft such as is seen in FIG. 1, and theviewing portion of the endoscope is positioned within a transparent noseportion located at the distal end of the shaft (Block 910). The shaft isinserted through the incision and adjacent to the vessel section to beharvested (Block 915). As the shaft is inserted, tissue is bluntlydissected away from the vessel (Block 920). The blunt dissection processis visually monitored using the endoscope (Block 925).

Once the blunt dissection process has been completed, the endoscope iswithdrawn from the shaft (Block 930), and a housing such as that seen inFIG. 3 is engaged with the inserted shaft by sliding the housing ontothe shaft from the proximal end of the shaft toward the distal noseportion of the shaft (Block 935). The endoscope is then reintroducedinto the shaft (Block 940). It will be apparent to one skilled in theart that the housing need not be fully engaged with the shaft in orderfor the endoscope to be reintroduced into the shaft when using a devicesuch as that seen in FIGS. 1 through 7. One skilled in the art will alsorecognize that the endoscope need not be removed and reintroduced if thedevice is designed to accommodate the endoscope while the housing isbeing engaged with the shaft. For example, the endoscope need not bewithdrawn and reintroduced if a two-part handle is designed such thatthe housing section of the handle can accommodate the endoscope whilethe housing is being engaged with the shaft or if a single handle isremovable.

Harvesting operations such as cutting and cauterizing side branches ofthe vessel or severing the vessel are performed in a working areadefined by sidewalls of the housing (Block 945). The harvestingoperations are visually monitored through a transparent bottom portionof the shaft using the endoscope (Block 950). The endoscope can be movedwithin the shaft lumen to best view the area of operations. Once theharvesting operations have been completed, the shaft and housing areremoved from the body (Block 955) as is the harvested vessel (Block960).

It will be appreciated by those skilled in the art that while theinvention has been described above in connection with particularembodiments and examples, the invention is not necessarily so limited,and that numerous other embodiments, examples, uses, modifications anddepartures from the embodiments, examples and uses are intended to beencompassed by the claims attached hereto. The entire disclosure of eachpatent and publication cited herein is incorporated by reference, as ifeach such patent or publication were individually incorporated byreference herein.

1. A device for harvesting a vessel section from tissue within apatient's body, comprising: a shaft including a lumen extending from aproximal end of the shaft into a distal nose portion of the shaft, thedistal nose portion of the shaft shaped for blunt dissection of thetissue through an incision adjacent the vessel section to be harvested,the shaft including a region along a length of the shaft through whichthe blunt dissection may be viewed; and a housing including an elongatedopening to provide a working area adjacent to the vessel section to beharvested, the housing engagable with the shaft by sliding the housingonto the proximal end of the shaft and toward the distal nose portion ofthe shaft along the vessel section to be harvested to a position inwhich at least a portion of the working area may be viewed through theshaft.
 2. The device of claim 1 wherein a bottom portion of the shaftcomprises a transparent material to provide a viewable region along alength of the shaft.
 3. The device of claim 2 wherein the bottom portionof the shaft is substantially planar.
 4. The device of claim 2 whereinthe bottom portion of the shaft forms a portion of a wall of the lumenextending from the proximal end of the shaft into the distal noseportion of the shaft.
 5. The device of claim 1 wherein the distal noseportion of the shaft comprises a transparent material to provide aviewable region adjacent to the nose portion.
 6. The device of claim 1wherein the housing includes a slot along a length of the housing, theslot having at least one opening into the working area, the slotreceiving at least a portion of the shaft to slidably engage the housingwith the shaft.
 7. The device of claim 1 wherein a proximal portion ofthe housing includes at least one tool passageway to the working area.8. The device of claim 1 wherein the housing is connected to a lightsource, and wherein the housing transmits light from the light sourceinto the working area.
 9. The device of claim 8 wherein the housingserves as a light pipe.
 10. The device of claim 1 further comprising: ahandle.
 11. The device of claim 10 wherein the handle is attached to oneof a proximal portion of the shaft or a proximal portion of the housing.12. The device of claim 10 wherein the handle comprises a shaft sectionand a housing section, and wherein the shaft section of the handle isattached to a proximal portion of the shaft and the housing section ofthe handle is attached to a proximal portion of the housing.
 13. Thedevice of claim 12 wherein the housing section of the handle includes acavity, and wherein at least a portion of the shaft section of thehandle is received within the cavity.
 14. The device of claim 12 whereinthe housing section of the handle includes at least one tool passagewayto the working area.
 15. The device of claim 10 wherein the handleincludes at least one endoscope passageway, the passageway incommunication with the shaft lumen when the housing is engaged with theshaft.
 16. A system for harvesting a vessel section from tissue within apatient's body, comprising: an endoscope; at least one harvesting tool;and an elongated instrument comprising a shaft and a housing, the shafthaving a region along a length of the shaft engaged with the endoscopethrough which tissue may be viewed while the shaft is in use, the shafthaving a distal nose portion shaped for blunt dissection of the tissuethrough an incision adjacent the vessel section to be harvested, thehousing having an elongated opening to provide a working area adjacentto the vessel section to be harvested in which the harvesting tool maybe operated to effect harvesting of the vessel, the housing engagablewith the shaft by sliding the housing onto the proximal end of the shaftand toward the distal nose portion of the shaft along the vessel sectionto be harvested to a position in which at least a portion of theharvesting tool in the working area may be viewed through the endoscopeengaged with the shaft.
 17. The system of claim 16 wherein a bottomportion of the shaft comprises a transparent material to provide aviewable region along a length of the shaft.
 18. The system of claim 17wherein the bottom portion of the shaft is substantially planar.
 19. Thesystem of claim 17 wherein the bottom portion of the shaft forms aportion of a wall of the shaft lumen.
 20. The system of claim 16 whereinthe distal nose portion of the shaft comprises a transparent material toprovide a viewable region adjacent to the nose portion.
 21. The systemof claim 16 wherein the housing includes a slot along a length of thehousing, the slot having at least one opening into the working area, theslot receiving at least a portion of the shaft to engage the housingwith the shaft.
 22. The system of claim 16 wherein a proximal portion ofthe housing includes at least one tool passageway to the working area.23. The system of claim 16 wherein the housing is connected to a lightsource, and wherein the housing transmits light from the light sourceinto the working area.
 24. The system of claim 23 wherein the housingserves as a light pipe.
 25. The system of claim 16 wherein the elongatedinstrument further comprises a handle.
 26. The system of claim 25wherein the handle is attached to one of a proximal portion of the shaftor a proximal portion of the housing.
 27. The system of claim 15 whereinthe handle comprises a shaft section and a housing section, and whereinthe shaft section of the handle is attached to a proximal portion of theshaft and the housing section of the handle is attached to a proximalportion of the housing.
 28. The system of claim 27 wherein the housingsection of the handle includes a cavity, and wherein at least a portionof the shaft section of the handle is received within the cavity. 29.The system of claim 27 wherein the housing section of the handleincludes at least one tool passageway to the working area.
 30. Thesystem of claim 25 wherein the handle includes at least one endoscopepassageway, the passageway in communication with the shaft lumen whenthe housing is engaged with the shaft.